initial commit

.gitignore

@@ -0,0 +1,2 @@
+/node_modules/
+*.zone

package.json

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+{
+  "name": "icy-dyndns",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "express": "^4.17.1",
+    "express-async-errors": "^3.1.1"
+  },
+  "devDependencies": {
+    "@types/express": "^4.17.11",
+    "@types/node": "^15.3.0",
+    "typescript": "^4.2.4"
+  }
+}

src/.gitignore

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+**/*.js
+**/*.d.ts

src/dns/cache.ts

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+import { CachedZone, DNSRecord, DNSZone, SOARecord } from "../models/interfaces";
+import { readZoneFile } from "./reader";
+import { DNSRecordType } from "./records";
+import { writeZoneFile } from "./writer";
+
+export class DNSCache {
+  private cached: Record<string, CachedZone> = {};
+
+  constructor(private ttl = 1600) {}
+
+  has(name: string): boolean {
+    return this.cached[name] != null;
+  }
+
+  async get(name: string): Promise<CachedZone | null> {
+    const cached = this.cached[name];
+    if (!cached) {
+      return null;
+    }
+
+    if (cached.changed.getTime() < new Date().getTime() - this.ttl * 1000) {
+      return this.load(name, cached.file);
+    }
+
+    return this.cached[name];
+  }
+
+  async set(name: string, zone: CachedZone): Promise<void> {
+    this.cached[name] = zone;
+  }
+
+  async load(name: string, file: string): Promise<CachedZone> {
+    const zoneFile = await readZoneFile(file);
+    const cache = {
+      name,
+      file,
+      zone: zoneFile,
+      added: new Date(),
+      changed: new Date()
+    }
+    this.cached[name] = cache;
+    return cache;
+  }
+
+  async save(name: string): Promise<void> {
+    const zone = await this.get(name);
+    if (!zone) {
+      throw new Error('No such cached zone file!');
+    }
+    await writeZoneFile(zone.zone, zone.file);
+  }
+
+  async update(name: string, newZone?: CachedZone): Promise<void> {
+    let zone: CachedZone | null;
+    if (newZone) {
+      zone = newZone;
+    } else {
+      zone = await this.get(name);
+    }
+
+    if (!zone) {
+      throw new Error('No such cached zone file!');
+    }
+
+    zone.changed = new Date();
+    const soa = zone.zone.records.find((record) => record.type === DNSRecordType.SOA) as SOARecord;
+    soa.serial = Math.floor(Date.now() / 1000);
+
+    this.set(name, zone);
+    return this.save(name);
+  }
+}

src/dns/reader.ts

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+import * as fs from 'fs/promises';
+import { DNSRecord, DNSZone, SOARecord } from '../models/interfaces';
+import { DNSRecordType } from './records';
+
+function cleanString(str: string): string {
+  return str.replace(/;[^"]+$/, '') // Remove comments from the end
+            .replace(/\s+/g,' ') // Remove duplicate whitespace
+            .trim(); // Remove whitespace from start and end
+}
+
+function parseRecordLine(line: string, index: number, lines: string[]): DNSRecord | SOARecord | null {
+  let actualLine = '';
+  let clean = cleanString(line);
+  if (clean.includes('(')) {
+    actualLine += clean;
+    const trimLines = lines.slice(index + 1);
+    for (const trimLine of trimLines) {
+      actualLine += ' ' + cleanString(trimLine);
+      if (trimLine.includes(')')) {
+        break;
+      }
+    }
+    actualLine = cleanString(actualLine.replace(/\(|\)/g, ''));
+  } else {
+    actualLine = clean;
+  }
+
+  const split = actualLine.split(' ');
+  if (split[0] === 'IN' && split[1] === 'NS') {
+    return {
+      name: '',
+      type: DNSRecordType.NS,
+      value: split.slice(2).join(' '),
+    }
+  }
+
+  if (split[2] === 'SOA') {
+    return {
+      name: split[0],
+      type: DNSRecordType[split[2]],
+      value: split.slice(3).join(' '),
+      nameserver: split[3],
+      email: split[4],
+      serial: parseInt(split[5], 10),
+      refresh: parseInt(split[6], 10),
+      retry: parseInt(split[7], 10),
+      expire: parseInt(split[8], 10),
+      minimum: parseInt(split[9], 10),
+    };
+  }
+
+  if (!actualLine.includes('IN')) {
+    return null;
+  }
+
+  return {
+    name: split[0],
+    type: DNSRecordType[<keyof typeof DNSRecordType>split[2]],
+    value: split.slice(3).join(' ')
+  }
+}
+
+export function parseZoneFile(lines: string[]): DNSZone {
+  let ttl = 0;
+  const includes = [];
+  const records: DNSRecord[] = [];
+
+  for (const index in lines) {
+    const line = lines[index];
+    if (line.startsWith('$TTL')) {
+      ttl = parseInt(line.split(' ')[1], 10);
+      continue;
+    }
+
+    if (line.startsWith('$INCLUDE')) {
+      includes.push(...line.split(' ').slice(1));
+      continue;
+    }
+
+    const record = parseRecordLine(line, parseInt(index, 10), lines);
+    if (record) {
+      records.push(record);
+    }
+  }
+
+  return {
+    ttl, includes, records
+  }
+}
+
+export async function readZoneFile(file: string): Promise<DNSZone> {
+  const lines = await fs.readFile(file, { encoding: 'utf-8' });
+  const splitLines = lines.split('\n');
+  return parseZoneFile(splitLines);
+}

src/dns/records.ts

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+export enum DNSRecordType {
+  A = 'A', AAAA = 'AAAA', AFSDB = 'AFSDB', APL = 'APL', CAA = 'CAA', CDNSKEY = 'CDNSKEY', CDS = 'CDS', CERT = 'CERT',
+  CNAME = 'CNAME', CSYNC = 'CSYNC', DHCID = 'DHCID', DLV = 'DLV', DNAME = 'DNAME', DNSKEY = 'DNSKEY', DS = 'DS',
+  EUI48 = 'EUI48', EUI64 = 'EUI64', HINFO = 'HINFO', IPSECKEY = 'IPSECKEY', KEY = 'KEY', KX = 'KX', LOC = 'LOC',
+  MX = 'MX', NAPTR = 'NAPTR', NS = 'NS', NSEC = 'NSEC', NSEC3 = 'NSEC3', NSEC3PARAM = 'NSEC3PARAM',
+  OPENPGPKEY = 'OPENPGPKEY', PTR = 'PTR', RRSIG = 'RRSIG', RP = 'RP', SIG = 'SIG', SMIMEA = 'SMIMEA', SOA = 'SOA',
+  SRV = 'SRV', SSHFP = 'SSHFP', TA = 'TA', TKEY = 'TKEY', TLSA = 'TLSA', TSIG = 'TSIG', TXT = 'TXT', URI = 'URI',
+  ZONEMD = 'ZONEMD', SVCB = 'SVCB', HTTPS = 'HTTPS', AXFR = 'AXFR', IXFR = 'IXFR', OPT = 'OPT', Wildcard = '*'
+}

src/dns/writer.ts

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+import * as fs from 'fs/promises';
+import { DNSZone, SOARecord } from '../models/interfaces';
+import { DNSRecordType } from './records';
+
+function createSOAString(record: SOARecord, padI: number, padJ: number): string[] {
+  const name = record.name.padEnd(padI, ' ');
+  const type = record.type.toString().padEnd(padJ, ' ');
+  const padK = ' '.padStart(
+    padI + 3
+  );
+  const padL = ['serial', 'refresh', 'retry', 'expire', 'minimum']
+    .reduce((previous, current) => {
+      const len = `${record[current]}`.length;
+      return previous > len ? previous : len;
+    }, 0) + 1;
+  return [
+    `${name} IN ${type} ${record.nameserver} ${record.email} (`,
+    `${padK} ${record.serial.toString().padEnd(padL, ' ')} ; Serial`,
+    `${padK} ${record.refresh.toString().padEnd(padL, ' ')} ; Refresh`,
+    `${padK} ${record.retry.toString().padEnd(padL, ' ')} ; Retry`,
+    `${padK} ${record.expire.toString().padEnd(padL, ' ')} ; Expire`,
+    `${padK} ${record.minimum.toString().padEnd(padL, ' ')} ; Minimum`,
+    `)`
+  ];
+}
+
+export function createZoneFile(zone: DNSZone, preferredLineLength = 120): string[] {
+  const file: string[] = [];
+  file.push(`$TTL ${zone.ttl}`);
+
+  let longestName = 0;
+  let longestType = 0;
+
+  // First pass: for nice alignments
+  zone.records.forEach((record) => {
+    if (record.name.length > longestName) {
+      longestName = record.name.length;
+    }
+
+    if (record.type.toString().length > longestType) {
+      longestType = record.type.toString().length;
+    }
+  });
+
+  zone.records.forEach((record) => {
+    if (record.type === DNSRecordType.SOA) {
+      file.push(...createSOAString(record as SOARecord, longestName, longestType));
+      return;
+    }
+
+    const name = record.name.padEnd(longestName, ' ');
+    const type = record.type.toString().padEnd(longestType, ' ');
+    file.push(`${name} IN ${type} ${record.value}`);
+  });
+
+  zone.includes.forEach((include) => {
+    file.push(`$INCLUDE ${include}`);
+  });
+
+  return file;
+}
+
+export async function writeZoneFile(zone: DNSZone, file: string): Promise<string[]> {
+  const fullText = createZoneFile(zone);
+  await fs.writeFile(file, fullText.join('\n'));
+  return fullText;
+}

src/index.ts

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+import express, { ErrorRequestHandler, NextFunction, Request, Response } from 'express';
+import 'express-async-errors';
+import path from 'path';
+import { DNSCache } from './dns/cache';
+import { DNSRecordType } from './dns/records';
+import { createZoneFile } from './dns/writer';
+import { fromRequest } from './ip/from-request';
+import { CachedZone, DNSRecord } from './models/interfaces';
+
+const port = parseInt(process.env.PORT || '9129', 10);
+const dir = process.env.ZONEFILES || '.';
+
+const app = express();
+const api = express.Router();
+
+app.use(express.json());
+
+const cache = new DNSCache();
+const weHave = ['lunasqu.ee'];
+
+async function getOrLoad(domain: string): Promise<CachedZone> {
+  if (!cache.has(domain)) {
+    if (!weHave.includes(domain)) {
+      throw new Error('Invalid domain.');
+    }
+    return cache.load(domain, path.resolve(dir, `${domain}.zone`));
+  }
+
+  const get = await cache.get(domain);
+
+  if (!get) {
+    throw new Error('Misconfigured domain zone file.');
+  }
+
+  return get;
+}
+
+api.get('/records/:domain/download', async (req, res) => {
+  const domain = req.params.domain;
+  const cached = await getOrLoad(domain);
+  res.send(createZoneFile(cached.zone).join('\n'));
+});
+
+api.get('/records/:domain', async (req, res) => {
+  const domain = req.params.domain;
+  const cached = await getOrLoad(domain);
+
+  const type = req.query.type;
+  const name = req.query.name;
+  const value = req.query.value;
+
+  if (type || name || value) {
+    const results = cached.zone.records.filter((zone) => {
+      if (type && zone.type !== type) {
+        return false;
+      }
+
+      if (name && zone.name !== name) {
+        return false;
+      }
+
+      if (value && !zone.value.includes(value as string)) {
+        return false;
+      }
+
+      return true;
+    }).map((record) => {
+      const inx = cached.zone.records.indexOf(record);
+      return {
+        ...record,
+        index: inx
+      }
+    });
+
+    res.json({
+      records: results,
+    });
+
+    return;
+  }
+
+  res.json(cached.zone);
+});
+
+api.post('/records/:domain', async (req, res) => {
+  const domain = req.params.domain;
+  const index = parseInt(req.body.index, 10);
+  const setters = req.body.record;
+
+  const cached = await getOrLoad(domain);
+  const { zone } = cached;
+  if (index == null || isNaN(index) || !zone.records[index]) {
+    throw new Error('Invalid record index.');
+  }
+
+  const keys = Object.keys(setters);
+  const record = zone.records[index];
+  if (!setters || keys.length === 0) {
+    res.json({ success: true, message: 'Nothing was changed.', record });
+    return;
+  }
+
+  if (setters.type) {
+    const upperType = setters.type.toUpperCase();
+    if (upperType === 'SOA' && record.type !== DNSRecordType.SOA) {
+      throw new Error('Cannot change type to Start Of Authority.');
+    }
+
+    if (!DNSRecordType[<keyof typeof DNSRecordType>upperType] && upperType !== '*') {
+      throw new Error('Unsupported record type.');
+    }
+  }
+
+  keys.forEach((key) => {
+    if (record[key]) {
+      record[key] = setters[key];
+    }
+  });
+
+  await cache.update(domain, cached);
+
+  res.json({ success: true, message: 'Record changed successfully.', record });
+});
+
+api.delete('/records/:domain', async (req, res) => {
+  const domain = req.params.domain;
+  const index = parseInt(req.body.index, 10);
+
+  const cached = await getOrLoad(domain);
+  const { zone } = cached;
+  if (!index || isNaN(index) || !zone.records[index]) {
+    throw new Error('Invalid record index.');
+  }
+
+  const record = zone.records[index];
+  if (record.type === DNSRecordType.SOA) {
+    throw new Error('Cannot delete the Start Of Authority record.');
+  }
+
+  zone.records.splice(index, 1);
+  await cache.update(domain, cached);
+
+  res.json({ success: true, message: 'Record deleted successfully.', record });
+});
+
+api.put('/records/:domain', async (req, res) => {
+  const domain = req.params.domain;
+  const setter = req.body.record;
+
+  if (!setter) {
+    throw new Error('New record is missing!');
+  }
+
+  const missing = ['name', 'type', 'value'].reduce<string[]>(
+    (list, entry) => (setter[entry] == null ? [...list, entry] : list)
+  , []);
+
+  if (missing.length) {
+    throw new Error(`${missing.join(', ')} ${missing.length > 1 ? 'are' : 'is'} required.`);
+  }
+
+  const { name, type, value } = setter;
+  const upperType = type.toUpperCase();
+  if (upperType === 'SOA') {
+    throw new Error('Cannot add another Start Of Authority record. Please use POST method to modify the existing record.');
+  }
+
+  if (!DNSRecordType[<keyof typeof DNSRecordType>upperType] && upperType !== '*') {
+    throw new Error('Unsupported record type.');
+  }
+
+  const cached = await getOrLoad(domain);
+  const { zone } = cached;
+  const newRecord = { name, type: upperType, value };
+  zone.records.push(newRecord);
+
+  await cache.update(domain, cached);
+  res.status(201).json({ success: true, message: 'Record added.', record: newRecord });
+});
+
+api.post('/dyndns/:domain', async (req, res) => {
+  const domain = req.params.domain;
+  const subdomain = req.body.subdomain || '@';
+  const waitPartial = req.body.dualRequest === true;
+  const { v4, v6 } = fromRequest(req);
+
+  if (!v4 && !v6) {
+    res.json({ success: true, message: 'Nothing to do.' });
+  }
+
+  const cached = await getOrLoad(domain);
+  const { zone } = cached;
+  const actions: string[] = [];
+
+  if (v4) {
+    const findFirstA = zone.records.find((record) =>
+      record.type === DNSRecordType.A && record.name === subdomain
+    );
+
+    if (!findFirstA) {
+      zone.records.push({
+        name: subdomain,
+        type: DNSRecordType.A,
+        value: v4
+      });
+      actions.push(`created A record ${v4}`);
+    } else {
+      if (findFirstA.value !== v4) {
+        findFirstA.value = v4;
+        actions.push(`updated A record with ${v4}`);
+      }
+    }
+  }
+
+  if (v6) {
+    const findFirstAAAA = zone.records.find((record) =>
+      record.type === DNSRecordType.AAAA && record.name === subdomain
+    );
+
+    if (!findFirstAAAA) {
+      zone.records.push({
+        name: subdomain,
+        type: DNSRecordType.AAAA,
+        value: v6
+      });
+      actions.push(`created AAAA record ${v6}`);
+    } else {
+      if (findFirstAAAA.value !== v6) {
+        findFirstAAAA.value = v6;
+        actions.push(`updated AAAA record with ${v6}`);
+      }
+    }
+  }
+
+  if (!actions.length) {
+    res.json({
+      success: true,
+      message: 'Up to date.',
+      actions
+    });
+    return;
+  }
+
+  if (waitPartial && ((v4 && !v6) || (!v4 && v6))) {
+    res.status(202).json({
+      success: true,
+      message: 'Waiting for next request..',
+      actions
+    });
+    return;
+  }
+
+  await cache.update(domain, cached);
+
+  res.json({
+    success: true,
+    message: 'Successfully updated zone file.',
+    actions
+  });
+});
+
+const errorHandler: ErrorRequestHandler = (err: any, req: Request, res: Response, next: NextFunction) => {
+  res.status(400).json({
+    success: false,
+    message: err.message
+  });
+}
+
+api.use(errorHandler);
+app.use('/api/v1', api);
+
+app.listen(port, () => console.log(`listening on ${port}`));

src/ip/from-request.ts

@@ -0,0 +1,51 @@
+import { Request } from "express";
+import { validv4, validv6 } from "./validators";
+
+export function fromRequest(req: Request): { v4: string | null, v6: string | null } {
+  let v4 = null;
+  const qv4 = req.query.ipv4 || req.body.ipv4;
+
+  let v6 = null;
+  const qv6 = req.query.ipv6 || req.body.ipv6;
+
+  // Lets begin our trials
+  // Determine Address from request headers
+  if (req.header('x-forwarded-for')) {
+    v4 = req.header('x-forwarded-for');
+  } else {
+    v4 = req.socket.remoteAddress;
+  }
+
+  if (v4 && !validv4(v4)) {
+    v6 = v4
+    v4 = null
+  }
+
+  // IPv4
+  if (qv4 && validv4(qv4)) {
+    v4 = qv4
+  }
+
+  if (qv4 === 'ignore') {
+    v4 = null
+  }
+
+  // IPv6
+  if (qv6 && validv6(qv6)) {
+    v6 = qv6
+  }
+
+  if (qv6 === 'ignore') {
+    v6 = null
+  }
+
+  if (v4 === null && v6 === null) {
+    return { v4, v6 };
+  }
+
+  // Remove subnet mask and prefix
+  if (v6) v6 = v6.replace(/\/(\d+)$/, '')
+  if (v4) v4 = v4.replace(/\/(\d+)$/, '')
+
+  return { v4, v6 };
+}

src/ip/validators.ts

@@ -0,0 +1,42 @@
+export function validv4(ipaddress: string): boolean {
+  if (/^(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$/.test(ipaddress)) {
+    return true
+  }
+  return false
+}
+
+export function validv6(value: string): boolean {
+  // See https://blogs.msdn.microsoft.com/oldnewthing/20060522-08/?p=31113 and
+  // https://4sysops.com/archives/ipv6-tutorial-part-4-ipv6-address-syntax/
+  const components = value.split(':')
+  if (components.length < 2 || components.length > 8) {
+    return false
+  }
+
+  if (components[0] !== '' || components[1] !== '') {
+    // Address does not begin with a zero compression ("::")
+    if (!components[0].match(/^[\da-f]{1,4}/i)) {
+      // Component must contain 1-4 hex characters
+      return false
+    }
+  }
+
+  let numberOfZeroCompressions = 0
+  for (let i = 1; i < components.length; ++i) {
+    if (components[i] === '') {
+      // We're inside a zero compression ("::")
+      ++numberOfZeroCompressions
+      if (numberOfZeroCompressions > 1) {
+        // Zero compression can only occur once in an address
+        return false
+      }
+      continue
+    }
+    if (!components[i].match(/^[\da-f]{1,4}/i)) {
+      // Component must contain 1-4 hex characters
+      return false
+    }
+  }
+
+  return true
+}

src/models/interfaces.ts

@@ -0,0 +1,32 @@
+import { DNSRecordType } from "../dns/records";
+
+export interface DNSRecord {
+  [key: string]: string | number;
+  name: string;
+  type: DNSRecordType;
+  value: string;
+}
+
+export interface SOARecord extends DNSRecord {
+  nameserver: string;
+  email: string;
+  serial: number;
+  refresh: number;
+  retry: number;
+  expire: number;
+  minimum: number;
+}
+
+export interface DNSZone {
+  ttl: number;
+  records: DNSRecord[];
+  includes: string[];
+}
+
+export interface CachedZone {
+  name: string;
+  file: string;
+  zone: DNSZone;
+  added: Date;
+  changed: Date;
+}

tsconfig.json

@@ -0,0 +1,71 @@
+{
+  "compilerOptions": {
+    /* Visit https://aka.ms/tsconfig.json to read more about this file */
+
+    /* Basic Options */
+    // "incremental": true,                         /* Enable incremental compilation */
+    "target": "es5",                                /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019', 'ES2020', or 'ESNEXT'. */
+    "module": "commonjs",                           /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', 'es2020', or 'ESNext'. */
+    // "lib": [],                                   /* Specify library files to be included in the compilation. */
+    // "allowJs": true,                             /* Allow javascript files to be compiled. */
+    // "checkJs": true,                             /* Report errors in .js files. */
+    // "jsx": "preserve",                           /* Specify JSX code generation: 'preserve', 'react-native', 'react', 'react-jsx' or 'react-jsxdev'. */
+    // "declaration": true,                         /* Generates corresponding '.d.ts' file. */
+    // "declarationMap": true,                      /* Generates a sourcemap for each corresponding '.d.ts' file. */
+    // "sourceMap": true,                           /* Generates corresponding '.map' file. */
+    // "outFile": "./",                             /* Concatenate and emit output to single file. */
+    // "outDir": "./",                              /* Redirect output structure to the directory. */
+    // "rootDir": "./",                             /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */
+    // "composite": true,                           /* Enable project compilation */
+    // "tsBuildInfoFile": "./",                     /* Specify file to store incremental compilation information */
+    // "removeComments": true,                      /* Do not emit comments to output. */
+    // "noEmit": true,                              /* Do not emit outputs. */
+    // "importHelpers": true,                       /* Import emit helpers from 'tslib'. */
+    // "downlevelIteration": true,                  /* Provide full support for iterables in 'for-of', spread, and destructuring when targeting 'ES5' or 'ES3'. */
+    // "isolatedModules": true,                     /* Transpile each file as a separate module (similar to 'ts.transpileModule'). */
+
+    /* Strict Type-Checking Options */
+    "strict": true,                                 /* Enable all strict type-checking options. */
+    // "noImplicitAny": true,                       /* Raise error on expressions and declarations with an implied 'any' type. */
+    // "strictNullChecks": true,                    /* Enable strict null checks. */
+    // "strictFunctionTypes": true,                 /* Enable strict checking of function types. */
+    // "strictBindCallApply": true,                 /* Enable strict 'bind', 'call', and 'apply' methods on functions. */
+    // "strictPropertyInitialization": true,        /* Enable strict checking of property initialization in classes. */
+    // "noImplicitThis": true,                      /* Raise error on 'this' expressions with an implied 'any' type. */
+    // "alwaysStrict": true,                        /* Parse in strict mode and emit "use strict" for each source file. */
+
+    /* Additional Checks */
+    // "noUnusedLocals": true,                      /* Report errors on unused locals. */
+    // "noUnusedParameters": true,                  /* Report errors on unused parameters. */
+    // "noImplicitReturns": true,                   /* Report error when not all code paths in function return a value. */
+    // "noFallthroughCasesInSwitch": true,          /* Report errors for fallthrough cases in switch statement. */
+    // "noUncheckedIndexedAccess": true,            /* Include 'undefined' in index signature results */
+    // "noPropertyAccessFromIndexSignature": true,  /* Require undeclared properties from index signatures to use element accesses. */
+
+    /* Module Resolution Options */
+    // "moduleResolution": "node",                  /* Specify module resolution strategy: 'node' (Node.js) or 'classic' (TypeScript pre-1.6). */
+    // "baseUrl": "./",                             /* Base directory to resolve non-absolute module names. */
+    // "paths": {},                                 /* A series of entries which re-map imports to lookup locations relative to the 'baseUrl'. */
+    // "rootDirs": [],                              /* List of root folders whose combined content represents the structure of the project at runtime. */
+    // "typeRoots": [],                             /* List of folders to include type definitions from. */
+    // "types": [],                                 /* Type declaration files to be included in compilation. */
+    // "allowSyntheticDefaultImports": true,        /* Allow default imports from modules with no default export. This does not affect code emit, just typechecking. */
+    "esModuleInterop": true,                        /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */
+    // "preserveSymlinks": true,                    /* Do not resolve the real path of symlinks. */
+    // "allowUmdGlobalAccess": true,                /* Allow accessing UMD globals from modules. */
+
+    /* Source Map Options */
+    // "sourceRoot": "",                            /* Specify the location where debugger should locate TypeScript files instead of source locations. */
+    // "mapRoot": "",                               /* Specify the location where debugger should locate map files instead of generated locations. */
+    // "inlineSourceMap": true,                     /* Emit a single file with source maps instead of having a separate file. */
+    // "inlineSources": true,                       /* Emit the source alongside the sourcemaps within a single file; requires '--inlineSourceMap' or '--sourceMap' to be set. */
+
+    /* Experimental Options */
+    // "experimentalDecorators": true,              /* Enables experimental support for ES7 decorators. */
+    // "emitDecoratorMetadata": true,               /* Enables experimental support for emitting type metadata for decorators. */
+
+    /* Advanced Options */
+    "skipLibCheck": true,                           /* Skip type checking of declaration files. */
+    "forceConsistentCasingInFileNames": true        /* Disallow inconsistently-cased references to the same file. */
+  }
+}